


A Part of the Plan

by alexcat



Category: Marvel Cinematic Universe
Genre: Angst, F/M, Fluff and Smut, Multi, Plot What Plot/Porn Without Plot, Post-Avengers: Infinity War Part 1 (Movie), Threesome - F/M/M
Language: English
Status: Completed
Published: 2019-07-31
Updated: 2019-07-31
Packaged: 2020-07-27 22:36:30
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,775
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20053636
Author URL: https://archiveofourown.org/users/alexcat/pseuds/alexcat
Summary: He hadn’t meant for any of it to happen.  As a matter of fact, the idea never crossed his mind.  Until it did.Tony accidentally stumbled upon Natasha and Steve, or was it all part of the plan?





	A Part of the Plan

**Author's Note:**

> I found this one in my files and finished it.

He hadn’t meant for any of it to happen. As a matter of fact, the idea never crossed his mind. Until it did. 

Stark was rambling around in the night as he had always done. He wished that sleep would come, but it was elusive, more elusive than ever since Titan. When he closed his eyes, he saw Peter Parker disappear in his arms. And if by chance he fell asleep, he woke sweating and sometimes even screaming. And Peter Parker still disappeared.

He knew Steve and Natasha were a thing. He hadn’t expected to find them in the common room, half naked and making out like teenagers, though. But there they were. 

They were on the sofa, his shirt was on the floor behind it. Her pants were on the coffee table. They were kissing and groping one another, by the looks of it, when he entered the room. He watched them for a few moments without making a sound. What struck him more than the eroticism of watching was their closeness, how they were so focused on one another, how they laughed softly and whispered to one another. 

He made a sound as if he’d just opened the door. Steve was startled but Natasha just gave him that smug grin of hers, the one that said she’d known he was there all along. 

“Hi, Tony,” Natasha said. “Join us?” He knew she was joking. Steve must not have because he coughed at her words. 

He decided to play along with her. “If I say yes?’ 

“Well, we’ll kiss you, too. And you have to take off something.”

Steve still looked rather stricken. 

“So do I get in the middle or uh-“

“Oh, the middle.”

“Who do I kiss?” Tony was loving the look on Rogers’ face. 

“Both of us. It wouldn’t be fair if we didn’t share alike, now would it?” Natasha said, still grinning.

He pulled the t-shirt he was attempting to sleep in off and dropped it where he stood. Natasha scooted over to make room for him between them. At this point, it was still a joke. 

“Who’s first?” he asked, knowing it would be Natasha.

“Steve. You kiss Steve, and if you do that, I know you’re serious.” 

Was she serious?

He looked at Steve, who looked a little like he was about to be beheaded. He put a hand on either side of Rogers’ face and touched his lips to Steve’s. So far, not too bad. 

“No, really kiss him.” Natasha was just being evil now. But he did it anyway. And Steve kissed him back, tentatively at first, then he parted his lips, letting Tony slide his tongue inside. One of them made a noise, a noise of pleasure. He wasn’t sure which. Steve must have not found it all as off putting as he’d acted like it might be.

Someone - Natasha was kissing the back of his neck. He shivered as goosebumps formed on his skin. She had removed her t-shirt and pressed her naked breasts to his back. 

“You’re shivering, Tony. Cold?” she whispered. 

“Not anymore,” he answered, between kisses with Steve. He realized that he _had_ been cold, ever since he and Nebula had gotten back from Titan.

Someone was tugging at his sweats and he realized it wasn’t Natasha. Steve! Fuck, they were going to do this. He’d had threesomes with women before and he’d been with a few guys when he was younger, just to see what it was like, but this – this was something else. These two were his best friends. 

Steve put his arms around Tony, so he was wrapped up with them on both sides. Though he was more excited than he’d been in a long time, he was also _not_ terrified for the first time in what seemed like years, but was maybe two or three days.

Steve and Natasha could keep the monsters at bay, if anyone could. 

He gasped aloud when one of them took him in hand and caressed him. He didn’t look to see which one of them it was. It didn’t matter anymore. 

“Let’s go to our room if we’re really going to do this,” Steve said. They gathered their clothes. Tony noticed that he and Natasha were naked already. They all tiptoed down the hall to Steve’s quarters. Natasha lit a couple of candles in the small bedroom. Thankfully, the room was small but the bed was not. They all moved to the bed.

“Off with the pants, Rogers,” Natasha told him. 

Steve was as ready as Tony felt. The man looked like a fucking god, almost as much as Thor did. Tony wanted to touch him. Steve moved him to the middle of the bed and flopped down on his side. He propped his head on his hand and smiled. 

“Posing?” Natasha asked. “Tony and I both know how pretty you are.” 

Steve might have blushed, though it was a little hard to tell in the candlelight. He did grin. 

“Come on, Cap. You gotta love the adoration,” Tony said. “We all see the way all the women here look at you. Like you’re a giant piece of cheesecake, well beefcake, but who the hell wants beefcake? What is beefcake anyway?” 

“Tony,” Natasha said. 

“Really, what is beefca-“ 

“Hush, Tony. Kiss him again. I want to watch you kiss him.” 

Tony kissed Steve, who growled a little when Tony melted into his arms. Natasha sat back and watched for a bit, then she moved over to be closer to them, pressing herself to Tony’s back again and putting her arms around him. Steve’s hand found hers and he squeezed it. Then he moved it down between them, where their erections were already rubbing against one another. She couldn’t hold both of them easily in one hand, but she and Steve could do it together. 

Tony moaned. “Oh, fuck.”

Steve made an inarticulate sound as he touched his forehead to Tony’s, looking into his eyes as Natasha encouraged them. “Yes, that’s it. I’ve wanted to get you together for a long time.”

Both Steve and Natasha’s hands were busy for the next few minutes. 

“I won’t be good for anything more if we don’t slow down,” Tony murmured against Steve’s mouth. 

Steve kissed him one more time and began to kiss down his body, kissing his chest first, ringing the old reactor scar with his tongue as Natasha moved so Tony could lay on his back. Natasha kissed him as Steve went further down. Tony was beginning to think that Steve wasn’t nearly as shocked as he’d seemed to be. 

“Did you two plan this? Not that it’s a problem, but it feels like you’ve talked about it before,” he said in a rush as Steve flicked his tongue over his testicles, sucking gently. “God, Rogers, where the hell did you learn that? No, don’t tell me now. I don’t want you to stop.”

“Hush, Tony,” Natasha said as she kissed him again. “We _have_ talked about it before,” she said as she began to move down, too, retracing the places that Steve had kissed. She paused again. “We talked about how we’d both wanted you and how we’d love to share you, to make love to you together. I’m not sure Steve took me seriously though.” 

She was close to Steve now. While he was between Tony’s spread open legs, she lay beside Tony. While Steve still licked and sucked his balls, Natasha took his cock in her hand and lapped the head, swirling her tongue around it, spreading the clear drops already there, wetting his cock.

Tony was on fire. 

Natasha licked his length from base to the head again, sucking him into her mouth as she did so. Steve moved up to get on his haunches beside Tony’s head. Tony watched Steve as he ran his hand down his heavy cock and back up. Tony reached a hand out to touch him. 

“Yes,” Steve groaned as Tony stroked experimentally. Steve put one hand on the headboard and moved so Tony’s mouth was only inches from his erection. Tony lifted his head from the pillow and lapped at the silky smooth skin on the head of Steve’s cock. “Oh fuck yes,” Steve breathed as Tony took him into his mouth, little by little, inch by inch, until he had all his mouth could hold. 

Just as Steve started to move his hips and slowly fuck Tony’s mouth, Natasha moved, letting Tony slip free from her mouth, but just as he started to protest, she straddled him and he moaned with his mouth full of Steve when she took him into her hand, guiding him until he was completely sheathed inside her. 

He began to move his hand up and down Steve’s cock as Natasha rode him, a slow, torturous undulation. She was tight around him and hot as hell as she moved. 

Steve looked at Natasha, reaching out to take her hand in his. Tony saw the affection between them in the look they gave one another. 

Steve looked down at him and shifted his position a little, whispering Tony’s name as he increased his pace. Tony, using his hand and his tongue, kept up with Steve. Though Tony didn’t think he could become more aroused, he did when he saw Steve Rogers’ face as he was completely undone by pleasure. 

“Tony!” he cried out as he spilled into Tony’s mouth. Tony swallowed once and again several more times before Steve was done. 

Natasha tightened her grip on Tony’s hips, riding him harder. Steve moved behind her and she lay down over Tony, kissing him. It wasn’t until he felt Steve inside Natasha, too, that he realized that Steve was ready again. Steve rode them hard once he was enveloped inside Natasha. 

Tony came quite suddenly and quite intensely. Natasha was with him, biting her lip to stay quiet as he felt her body pulsate around him, drawing every drop from him before she slowed. Steve was only seconds behind them, crying out their names hoarsely as he drilled them both into the soft bed. 

They all separated slowly and Natasha and Steve lay on either side of Tony, Steve kissing his lips and Natasha kissing his cheek as they wrapped their arms around him and snuggled close. 

He felt something he hadn’t expected from them. He felt that they’d made room for him in their relationship, that it was his relationship, too, not just a one off. He decided not to overthink it and closed his eyes to rest. 

He was safe and he was warm. That was enough.

**Author's Note:**

> My [**Tumblr**](https://www.tumblr.com/blog/alexcat45).


End file.
